Roller gin with grooved square rotobar

ABSTRACT

A roller cotton gin including a ginning roller and a stationary knife to which seed cotton is conveyed by the friction surface of the ginning roller for separating lint fibers from the cotton seed, and a rotary stripping blade device adjacent the stationary knife formed from a square cross section bar having V-shaped grooves axially spanning each face adjacent the corners providing blade formations for advancing the seed cotton deposited on the surface of the ginning roller to the zone of the stationary knife. The seed cotton is received in and advanced by the channel-like spaces between successive blade formations, and the stripping blade device has a diameter which is a small fraction of the ginning roller diameter and rotates at a speed causing the surface speed of the blade edges to approximately the same as the surface speed of the ginning roller such as to restrain seeds in the channel-like spaces during seed advancement over the pinch point at the edge of the stationary knife to a release point while the ginning roller strips lint from the restrained seeds and then releasing the seeds from blade restraint at the release point after they travel about 1/2 the staple length beyond the pinch point to return any incompletely ginned seeds still having attached fiber to the knife edge before the next blade applies advancing force to the seed and thereby withdraw substantially all the fibers from the seed. Flexible strip-like pads provided in the channel-like spaces to press the seed cotton against the ginning roller surface, and an auxiliary feed control roller and an unginned seed restraining and recycling comb structure are also disclosed.

BACKGROUND AND OBJECTS OF THE INVENTION

The present invention relates in general to a cotton gin, and moreparticularly to a roller cotton gin constructed to strip lint from theseed of seed cotton with a high degree of efficiency and having highcapacity.

The ginning of cotton, which is the operation in which the seeds areseparated from the cotton fibers, is customarily carried out either in asaw gin or in a roller gin. The saw gin has been the dominant type forginning the fuzzy seed Upland Cotton while the saw gin has not beenacceptable for use on the Black Seed Cotton which generally has a longerstaple. When ginning the extra long staple Black Seed Cottons, which arecommonly referred to as a variation of Egyptian Cottons, on saw ginfiber, breakage results in a shorter staple and generally a lessdesirable fiber for the high-quality products for which this fiber isnormally used.

To generally distinguish between these two basic types of cotton, by farthe most common type of cotton is the Upland Cotton which varies instaple length from less than 3/4 inch to more than 11/8 inch. The seedsare fuzzy and each fiber is firmly attached to the seed. The cotton isalmost always saw ginned, although there are periodic efforts to rollergin the longer staple varieties to better preserve the fiber quality.

The other type of cotton is sometimes referred to as Black Seed Cotton,but more commonly referred to as extra long staple cotton. The staplelength of this cotton varies widely as with the Upland Cotton but themore common varieties are about 13/8 inch to 11/2 inch in staple length.The fibers are very fine and silky and can be used in very expensivematerials. Saw gins break and tangle these fine fibers which lowerstheir quality. Also, the fibers are so gently attached to the slicksurface of the seed, the performance of the saw gin is not verysatisfactory. For these reasons, this Black Seed Cotton is almost alwaysroller ginned.

A particular disadvantage has been encountered heretofore in connectionwith roller gins in that, whereas a saw gin produces fiberscontinuously, roller gins heretofore used are somewhat intermittent inoperation. This occurs because of the fact that there is a reciprocatingblade employed that cooperates with the ginning roller and a stationarydoctor knife to strip the seeds from the fibers as the fibers are drawnpast the doctor knife by the ginning roller. The reciprocation of themoving blade serves to interrupt the flow of cotton to the ginningroller so that in this type of roller gin, the productive rate of theroller gin has been relatively slow. The high quality of the fibersproduced by a roller gin, however, have caused it to continue in use,particularly in regions where the cotton is characterized byparticularly long fibers.

Various attempts have been made to improve the roller cotton gin and, inparticular, to improve the gin with respect to the rate of fiberproduction in order to reduce the cost of ginning the Black Seed Cotton,while at the same time retaining the advantageous characteristics of theroller gin that the fibers produced are not entangled or broken.

Much effort has been given to alleviating difficulties with the lengthof time required in roller gins to pull the fibers from the seed,particularly long fibers, and to dislodge the seed from the fibers withthe seeds in a relatively fiber-free condition, and do this continuouslyat a relatively high rate of speed. This has led to the construction ofa roller gin having a ginning roller turning against a stationary knifeso that the fibers will be drawn under the knife while the seeds areretained, and utilizing with this construction rotary or continuouslymoving knife means to knock the seeds away from the stationary knife.Difficulties have been encountered however in producing clean seeds withthis construction because not enough ginning time was given to pull thefibers off the seeds and some considerable seed cracking occurred.

In the case of roller gin employing a reciprocating blade for thepurpose of disloding the seeds from the stationary knife, it has beenproposed to have the moving blade overlap the stationary knife by about1/2 the length of the staple of the cotton being ginned. Fibers arepulled, by friction of the ginning roller, under the knife until theseed is against the knife edge. The friction is not always great enoughto pull all the fibers from the seed, in which case it is necessary forthe blade to push the seed away from the knife's edge. In the case ofthe reciprocating blade, it operates parallel and close to the topsurface of the blade to push the seed away. If the seed is not pushedbeyond the length of most of the fibers, the friction on the fibersstill held between the roller and the knife will draw the seed back tothe knife, at which time most if not all the fibers are removed. It isdifficult to determine accurately how many times an individual seedreturns before all fibers are removed, as this depends on a number ofvariables, the most obvious one being the pressure of the ginning rolleragainst the knife. The pressure can be enough for the friction to removepractically all the fibers as the seeds are pushed away by the blade.However, such pressure will usually cause the roll to overheat.

The overlap of the reciprocating blade of approximately one half thestaple length has been accepted by those experienced in ginning extralong staple cottons for many years. The fact that the reciprocatingblade completely blocks the access of the cotton to the ginning rollerduring its travel across the knife limits the capacity of such a methoddrastically. The economics of this method limit its use to the verylongest staple of high quality whose value would be greatly reduced bysaw ginning.

Literally hundreds of roller ginning machines have been designed in aneffort to increase the capacity and thus reduce the cost of rollerginning. In spite of these efforts the reciprocating blade methodprevailed through the 1950's. Subsequently, as a result of work by someengineers engaged in a program to prove methods of roller ginning at theUnited States Department of Agriculture's Ginning Laboratory at MesillaPark, N. Mex., there appeared in about 1961 a roller gin design usingsquare bars mounted on a driven chain system to travel over a knife,allowing the cotton to be fed to the ginning roller between the bars.This was called "the flight bar gin". Several companies manufactured andinstalled elaborate and expensive plants using the flight bar ginprinciple, but these plants were not successful, because it was notpossible to maintain the required pressure on the flight bars as theymoved over the knife, since sprocket and chain wear necessitatedconstant adjustment.

In analyzing the difficulties encountered with the flight bar gin andstudying the art, I concluded that a rotating blade would serve the samepurpose as the flight bar or the old reciprocating bar and permitattainment of improved roller ginning. Study of the art showed thatrotating blades, such as blades on a rotating cylinder, had beenpreviously tried and found to be unsuccessful, but the rotatingcylinders with blades in those cases were approximately the diameter ofthe ginning roller which allowed for an overlap much greater than thestaple length. I determined that many of the problems previouslyencountered with such large diameter rotating blades or with the flightbars should be alleviated by using a rotating blade about 23/4 inches indiameter and an overlap with the knife of about 3/4 inch and a number ofroller gins having this dimensional relationship and arrangement havebeen previously used for cottons having a staple length of, for example,about 13/8 inch to 1 1/2 inch.

I have devoted considerable study to investigation of the optimumdiameter, speed and configuration of the rotating blade device and theoverlap, particularly with regard to roller ginning of the shorterstaple cotton. My studies indicate that for Upland Cotton, the bladedevice should be about 2 inches in diameter to achieve optimum releaseof the seed after about 1/2 inch to 5/8 inch movement. In consideringthe configuration to maintain the required rigidity with such a smalldiameter blade and the number of blades to be provided, the R.P.M. is afactor. A study of the relationship of the surface speed of the rotatingblade to that of the ginning roller indicates that the ratio shouldapproach 1:1. If the ginning roller, as it approaches the ginning point,is fully covered with cotton, and the surface speed of the rotatingblade is significantly less than that of the ginning roller, there wouldbe intermittent build-ups of cotton ahead of the rotating blade as eachblade comes into ginning position. These build-ups overload the ginningcapacity of the ginning roller intermittently, resulting in thenecessity to cut back the feed. The build-ups can be eliminated bysetting up the surface speeds of the ginning roller and rotating bladeto be close to the same speed.

With this established, the question of the number of blades on therotating blade assembly can be determined within reasonable limits. Asthe seed is pushed away from the ginning point to the release positionit must have time to return to the ginning point before the next blademoves to the ginning point. The travel of the ginning roller surfacemust be enough to pull the seed back to the knife before the next bladereaches the knife edge.

It has been determined that for Upland Cotton, a rotating blade assemblyof about 2 inches in diameter and having four blade points or blademembers more nearly meet this criteria. As one means of achieving thisin a simple manner, I have used a 11/2 inch by 11/2 inch square crosssection bar which is machined to a configuration to provide four bladeformations at the four corners by providing a V-cut vein or groovespanning the axial length of the bar immediately adjacent each of thefour corners on the side thereof in the direction of rotation of therotating blade assembly. The diagonal dimension of this square bar is2.12 inches, which is very close to the calculated 2 inch diameterdetermined to be appropriate to meet these criteria. This grooved squarecross section rotating blade or rotobar, when arranged adjacent theginning roller and the stationary knife, has shown capacities which aremuch superior to any obtained on prior units, particularly where areasonably low residual lint on the seed is maintained. By thisarrangement, the rotating blades formation at the corners of the squarebar with the V-cut grooves move the seed away from the knife edge, andthen allow them to return to the knife edge before the next blade hitsthe seed, and maintains a surface speed relationship of the two rollersthat will avoid an accumulation of unginned cotton on the ginning rollerahead of the rotating blade. Of course, if more than four blades areused on the rotating blade assembly, the speed of the rotating bladeshas to be reduced or the speed of the ginning roller increased to avoidhaving the blade hit the seed before it returns to the knife edge, thusleaving lint on the seed. For extra long staple, of the order of 13/4inch to 11/2 inch, the diameter of the four point rotating bladeassembly may be increased to approximately 3 inches.

While such a roller gin with the grooved sqaure cross section rotobar orrotary blade device having approximately a 11/2 inch by 11/2 inch squarecross section for Upland Cotton achieved the desired result of pushingthe seed away from the ginning point to the release position and thenallowing it to return to the ginning point before the next blades movesto the ginning point, to achieve high capacity ginning, it was foundthat a certain number of seed locks are carried over the point ofcontact of the stationary knife and the ginning roller surface, referredto as the pinch point, without being ginned. This was primarily due tothe fact that they are carried rapidly by the blades of the rotary bardevice and the fibers failed to get picked as they crossed the pinchpoint. These unginned locks would then be intermingled with the ginnedseed and be reclaimed and returned through the system. I have discoveredthat by providing a pad or strip of flexible material on the flatsurface of the square cross section grooved rotary bar device of suchdimension as to press the seed locks against the ginning point, thepercentage of unginned seed locks is drastically reduced and thecapacity is increased accordingly. Preferably, use of a piece of felt orsponge rubber, for example about 1/4 inch by 5/8 inch in cross section,bonded to the center of the flat surface and spanning the length of therotary bar device provides satisfactory results. This expedient ofproviding a pad of flexible material along the midregion betweensuccessive blades of a rotobar or rotating blade assembly also improvesthe performance of conventional rotary blade devices formed of a roundcenter shaft and 4 or more radial blades having the flexible pads in thebase region of each pocket between successive blades.

An object of the present invention, therefore, is the provision of anovel roller gin construction having a rotating blade or rotobar deviceof small diameter and novel construction arranged immediately adjacentthe working or leading end of the stationary knife, having anappropriate configuration and surface speed and spacing between bladesto move the seed away from the knife edge and then allow it to return tothe knife edge before the next blade hits the seed, and maintaining thesurface speed relationship between the rotating blade assembly and theginning roller so as to avoid an accumulation of unginned cotton on theginning roller ahead of the rotating blade.

Another object of the present invention is the provision of a novelroller gin having a rotating blade or rotobar device of small diameterrelative to the diameter of the ginning roller formed of square crosssection having V-shaped veins or grooves immediately adjacent thecorners to define seed-engaging blades and seed receiving pocketstherebetween so correlated to the seed size and to the speed of rotationof the ginning roller and the rotating blade device as to cause the seedto be pushed away from the ginning point or pinch point to a releasepoint by engagement with the blade-like surfaces on the rotating bladedevice and then have time to return to the pinch point before the nextblade-like surface moves to the pinch point, the release point beingsuch that the seeds are not pushed out of the ginning zone with fibersstill attached.

Yet another object of the present invention is the provision of a novelroller gin construction having a rotating blade device adjacent the edgeof the stationary knife provided with plural blades transverselyspanning the width of the gin formed from a square cross section memberproviding a blade device of small diameter compared to the diameter ofthe ginning roller having a surface speed close to the surface speed ofthe ginning roller, and having flexible pads between the successiveblades to press the cotton seed locks against the ginning point andreduce the percentage of unginned locks.

Other objects, advantages and capabilities of the present invention willbecome apparent from the following detailed description, taken inconjunction with the accompanying drawings illustrating preferredembodiments of the invention.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a diagrammatic elevational view of a roller cotton ginembodying the present invention;

FIG. 2 is a vertical section view through the roller gin of the presentinvention, taken substantially along the longitudinal mid-plane of thegin;

FIG. 3 is a fragmentary vertical section view, to enlarged scale,showing the rotating blade device and the stationary knife and ginningroller portions of the gin;

FIG. 4 is a fragmentary perspective view of the blade device used withthe roller gin of the present invention;

FIGS. 5 and 5A are fragmentary section views similar to FIG. 3,illustrating modified forms of roller gin embodying the presentinvention, FIG. 5A having an auxiliary roller associated with therotating blade device; and

FIGS. 6a and 6b are end elevation and fragmentary front elevation viewsof a modification wherein a comb or rib device is associated with therotating blade assembly to return unginned locks to the ginning process.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to the drawings, wherein like reference characters designatecorresponding parts throughout the several figures, and particularly tothe embodiments shown in FIGS. 1 to 4, the roller cotton gin of thepresent invention is indicated generally by the reference character 10,and in customary fashion, may be preceded by a distributor, indicatedgenerally at 12 in the diagrammatic elevational view of FIG. 1, with afeeder, indicated generally at 14, interposed between the distributor 12and the roller cotton gin 10. The cotton to be ginned is fed into themachine by way of feeder 14, in one suitable example, and the lintfibers that are separated from the seed are discharged into a lint ductor flue 18 for transporting the fibers to the subsequent processingstation, such as a battery condenser, lint cleaner or other known lintprocessing equipment. The gin may be provided with any of a number ofarrangements for reprocessing or reclaiming unginned locks. As oneexample, a comb or rib structure as shown in FIGS. 6a, 6b, and ashereinafter described, may be provided to return unginned locks aroundthe rotary blade device to the pinch point for reprocessing. As anotherexample, there may be associated with the gin, as illustrated in FIGS. 1and 2, a reclaiming station as indicated diagrammatically at 20, wherethe unginned seeds that may pass the ginning station are separated fromthe ginned seeds and conveyed by a suitable return duct back to thedistributor or other suitable point in the plant.

The structure of the roller gin, and the associated feeder 14 and theoptional reclaiming unit 18 is illustrated in the vertical section viewof FIG. 2. The roller gin stand comprises, in accordance with usualpractice, a frame 22, made up of sheet metal and suitable bracingmembers to support the various operating components of the gin and alsoprovide support for the associated seed cotton feeder 14 which mounts ontop of the frame 22. The seed cotton feeder 14 includes a housing 24,also typically formed of sheet metal and bracing members, having shapedinterior sheet metal partitions 26 transversely spanning the width ofthe feeder and extending through the total height thereof defining agenerally vertically arranged passage 28 for transfer of the seed cottonfrom the lower outlet of the feeder 14 to the gin stand. Movement of theseed cotton through the passage 28 of the feeder is controlled by a pairof feed rollers 30, which are usually driven by an automaticallycontrolled variable drive mechanism, in accordance with conventionalpractice, in correlated relationship to the feed requirements of thegin, and transfer the cotton to the zone of action of the large feedwheel 32 delivering the seed cotton to the downwardly inclined slide 34within the upper portion of the gin stand 10.

The cotton being delivered at a controlled rate from the lower dischargeend of the feeder 14 and downwardly along the inclined slide or feedchute 34 is deposited by gravity onto the top of the ginning roller 36which has a friction surface or cover 38 of leather or rubber-likematerial of such a nature that the fibers of the cottom tend to adherethereto so that the cotton is carried around the ginning roller in thedirection of the arrow 36' toward the stationary ginning knife 40. Tocooperate with the ginning roller 36 and stationary ginning knife 40 inremoving seed from the seed cotton, a rotating blade seed strippermember, which I refer to as a rotobar blade assembly 42 is providedimmediately adjacent the leading or upstream edge 40a of the ginningknife, for example, with its center axis laying substantially in theradial plane extending from the center axis of the ginning roller 36through the leading edge 40a of the ginning knife.

The rotobar blade assembly 42 of the present invention is formed of a11/2 inch by 11/2 inch square cross section bar for Upland Cotton, and a2 inch by 2 inch square cross section for extra long staple, having forexample, cylindrical outer ends of the same or slightly smaller diameterthan the thickness of the bar journaled in suitable bearings (not shown)in the side wall of the gin stand. The square cross section portion 44of the bar extends substantially the full width of the gin stand and ismachined to a configuration to provide 4 blade formations 46 at the 4corners of the square bar portion by providing a V-cut vein or groove 48spanning the axial length of the square bar portion 44 immediatelyadjacent each of the 4 corners on the side thereof in the direction ofrotation of the rotating blade assembly, whereby one of the sides 48a ofthe V-cut forms a blade surface facing forwardly relative to thedirection of rotation of the rotorbar 42 to engage and move the seedsover the leading edge of the stationary knife 40. In one specificexample, the 11/2 inch by 11/2 inch square cross section bar is machinedto provide cylindrical end portions having a diameter of about 1 7/16inch to be journaled in the bearings at the sides of the gin stand andthe V-cuts 48 adjacent the 4 corners 46a of the square cross section barportion 44 are cut to provide sides 48a and 48b which are each atapproximately 45° angles to the surface of the bar in which they are cutwith each of the sides 48a, 48b having a width of about 5/16 inch, theedge of the V-cut side 48a intersecting the surface of the bar portion44 in which it is cut approximately 1/16 inch from the adjacent corner46a and the other side 48b of the V-cut intersecting the bar surfaceapproximately 1/2 inch from the adjacent corner 46a. The diagonaldimension of this square bar is therefore approximately 2.12 inches,providing the small diameter rotating blade assembly which can beconveniently operated at speeds appropriate to release the seed afterabout 1/2 inch to 5/8 inch movement, or about half the staple length,after the seed is moved over the edge 40a of the stationary knife 40 atthe pinch point P. While the use of such a rotobar or rotary bladeassembly 42 as above described provides capacities much superior tothose obtainable with prior roller gins, the number of unginned lockswhich may pass over the point of contact of the stationary knife withthe ginning roller surface, which would have to be reclaimed orreprocessed in some manner, can be further reduced by providing on eachof the flat faces of the square cross section portion 44 of the rotobar42 which form the surfaces which extend inwardly from the cylindricalpaths swept by the edges or corners 46a of the blade formations 46, apad of flexible material in strip form, as indicated at 50 in FIGS. 4and 5, substantially centered on the associated side of the rotobar andextending the axial length of the square cross section portion 44. Forexample, the flexible pad strip 50 may be formed of felt or spongerubber, having a cross-sectional dimension of about 1/4 inch by 5/8inch, bonded to the center of the flat surface of the associated side ofthe rotobar and extending the length of the square cross section portionthereof. The pad 50 should be flexible or soft enough to avoid crushingof the seed against the ginning roller, and serves to press the seedlocks against the ginning point as the blade formations 46 engage andmove the seeds across the top of the pinch point and the edge of thestationary knife 40.

I have also found that the small diameter of the rotobar blade device 42may sometimes cause an uneven flow of cotton between it and the ginningroller, when for example, some of the cotton approaches the rotobarabove its center line. A smoother, more uniform feed of the seed cottonto the rotobar device and the knife can be obtained by the arrangementof FIG. 5, where there is provided an auxiliary feed control roller 52spaced slightly upstream from the rotobar blade assembly 42 and locatedbetween the latter and the discharge end of the slide or feed chute 34.The auxiliary feed control roller 52, as shown in FIG. 5, is formed of acylindrical smooth surfaced roller member 54, having, for example, adiameter of about 2 15/16 inches (for the 11/2 inch by 11/2 inchrotobar) and reduced diameter ends journaled in bearings in the sidewalls of the frame 22 and positioned so that the cylindrical surface 54passes very close to the surface of the ginning roller 36 duringrotation of the auxiliary feed control roller 52.

By suitable means known to those skilled in the art, such as pulleys andmotor drive belts, not shown, the ginning roller 36, rotobar bladeassembly 42, and auxiliary feed control roller 52 are driven by drivemeans diagrammatically indicated at 36X and 42X in FIG. 1, in thedirections indicated by the arrows and at appropriate speeds to sweepthe outer free edges of the blade formations 46 of the rotobar 42 in thedirection indicated by the arrow 42a, to move them inwardly toward thefriction surface 38 of the ginning roller 36 and into the closestproximity to the surface 48 at the pinch point P just in advance of theleading or forward edge of the stationary knife 40. The stationaryginning knife 40 bears on the friction surface 38 of the ginning roller36 adjacent the rotobar blade assembly 42, and the fibers or lint of thecotton locks are drawn beneath the stationary ginning knife 40 while theseeds are prevented from passing beneath the knife because there is notsufficient clearance for the seeds. The fibers are thus pulled from theseeds by the friction surface 38 of the ginning roller as the ginningknife 40 restrains the seeds against movement and the seeds aredischarged above the ginning knife in the direction of the arrow 56. Thefibers or lint pulled under the ginning knife 40 by the friction surfaceof the ginning roller 36 pass into the outlet chamber 66 whichcommunicates with the lint duct or lint flue 18, while those fiberswhich remain adhered to the friction surface 38 of the ginning roller 36may be stripped therefrom, in accordance with conventional practice, byproviding a doffing roller 68 having flexible rubber-like blades 70which serve to strip the fibers from the friction surface.

It will be apparent that the use of the pads of flexible materialspanning the axial length of the working portion of the rotobar betweenthe blade formations is, in effect, located in the base or bottomsurface of the channel-like pockets formed between successivecircumferentially spaced blade formations, serving to resiliently pushthe seed locks into the pinch point. This use of flexible materialattached to the base surface portion of these channel-like formationsalso would serve a similar purpose in rotating blade assemblies of thetype shown in my earlier U.S. Pat. No. 3,251,094, for example, whereinblades are provided as a plurality of radial flat blade members fixed ina cylindrical center shaft forming channel-like pockets between thesuccessive blades as illustrated in FIG. 5A, where the pads 50' areprovided between the blades 48' of the blade assembly 42'. In eithercase, the flexible filler or pad between the successive bladesresiliently urging the seeds in the channel-like pocket formationsagainst the friction surface of the ginning roller further increases theassurance that at least a few fibers of each seed lock will be caughtbetween the knife 40 and the ginning roller surface 38 as the seedcotton is moved to the pinch point. Once a few fibers of the seed lockare caught between the stationary knife and the ginning roller surface,usually all of the fibers are then pulled from the seed before the seedis finally released to be discharged from the gin stand, since the seedis released from the blade which just carried it over the pinch pointafter travel for about 1/2 the staple length of its fibers and thus isdrawn back to the pinch point and engaged and moved by the nextsuccessive blade advancing to the pinch point so long as fibers remainon the seed and some fibers are caught between the knife and the ginningroller surface.

In the event the reclaiming device indicated generally at 20 in FIG. 1is associated with the roller gin, seeds that are discharged along thepath indicated by the arrow 56 above the ginning knife 40, after thelint has been removed from them, pass down a seed chute 72 and aresubjected to reclaiming processing by delivering them into the workingzone of a rotary saw 74, for example, where the lint fibers stilladhered to the seed that have not been completely cleaned of lint arecaught by the seed of the saw and carried past stationary bars 76through which the cleaned seeds pass and are removed through outletpassages 78. Seeds which still have sufficient lint on them to remaincaught on the saw teeth are carried to the doffing zone where thedoffing brush 80 removes them from the saw teeth and the incompletelyginned seeds with adhering lint fibers are then delivered by a returnduct 82 back to the inlet side of the cleaner and extractor 12.

Alternatively, an arrangement such as that illustrated in FIGS. 6a, 6bmay be provided, where, instead of providing the reclaiming mechanismdescribed above, a simple wire comb or rib-like structure 84 is providedadjacent the rotobar blade assembly 42, formed of a plurality orarcuately curved wire fingers 86 supported in downwardly extendingrelation from a supporting block 88 and extending in a concave,substantially semi-cylindrical path facing toward and substantiallyconcentric with the axis of the rotobar 42. The curved wire fingers 86lie in parallel vertical planes perpendicular to the axis of the rotobarwith the curved portions thereof spaced just outwardly of but close tothe free edges or corners of the blade formations 46, and are spacedtransversely apart a proper distance to permit passage of seedstherebetween but to return unginned cotton to the ginning process bycausing them to be carried back across the top of the rotobar and downagain to the pinch point P.

The ginning knife 40 is rigidly mounted in the supporting frame 90 fixedin the housing of the gin stand, while the ginning roller 36 may bemovably supported so that it can be adjusted toward and away from thestationary knife 40 and be caused to engage the knife 40 under varyingdegrees of pressure. The roller gin of the present invention operates toprovide for highly efficient ginning because of the action of thealtered square cross section rotobar 42 with its blade formations 46 andthe stationary knife 40 and friction surfaced ginning roller 36, and thecorrelation of sizes and surface speeds thereof. It will be appreciatedthat the blade formations 46 of the rotobar 42 rotate in such a paththat the outer tips or free edges of the blades described a circular orcylindrical path whose diameter is a small fraction, less than aboutone-fifth, of the diameter of the ginning roller 36, and the bladeformations 46 define between them a series of resilient-pad-bottomedpockets or channels which receive the unginned seed cotton dischargingfrom the feed chute 34 onto the upwardly facing surface portion of theginning roller 36 and carried thereby into the zone of action of therotobar 42. Assuming a 15 inch diameter ginning roller 36 operating inthe range of about 135 R.P.M. with Upland Cotton, the rotobar surfacespeed should be of the order of about 10 percent less than the speed ofthe ginning roller, or about 860 R.P.M., with a rotobar of the sizedescribed to provide the proper high capacity and effective ginning ofthe Upland Cotton cotton.

When the seed cotton enters the channels or pockets formed between theblade formations of the rotobar 42, and reaches the pinch point P, thefibers are drawn under the stationary knife 40 by their adherence to thefriction surface of the ginning roller 36 while the seed is restrainedagainst movement thereunder by the working edge of the stationary knife.The diameter of the rotobar 42 and its surface speed relative to thesurface speed of the ginning roller are such that the seed carriedthrough and beyond the pinch point while the fibers are being drawntherefrom beneath the knife 40 are released by the blade surface 48a ofthe rotobar which advanced then, after a travel of about 1/2 the staplelength from the pinch point, so that the seed is allowed to return tothe knife edge before the next blade surface 48a hits the seed. Thetravel of the ginning roller 38, of course, is enough to pull the seedback to the knife 40 before the next blade surface 48a reaches the knifeedge 40a, and thus the ginning roller 36 and stationary knife 40 coactto withdraw substantially all of the fibers from the seed so long assufficient fibers remain attached to the seed to continue drawing theseed back to the pinch point after each release by the traveling bladesurfaces. Tests of this construction have shown capacities which aremuch superior to any obtainable on prior roller gins, particularly wherea reasonably low residual lint on the seed is maintained. For example,ginning Upland Cotton with as low as 6.6 percent residual lint with a 4blade rotobar producing 2 bales per hour have been attained, whereasabout 12 percent residual lint occurs when the same cotton is ginned ona conventional saw gin.

What is claimed is:
 1. A roller cotton gin comprising a ginning rollerhaving a friction surface for conveying lint fibers to a pinch pointstation and a fixed knife for separating the lint fibers from cottonseed having an upstream facing working edge at the pinch point locatedsubstantially tangentially of and in contact with the surface of saidginning roller, a rotary feed blade rotobar member spanning the width ofthe gin having a center axis and shaped at circumferentially spacedlocations to form at least four forwardly facing blade surfaceformations spanning the gin width having outer edges located to sweepthrough an arcuate cylindrical path whose diameter is a small fractionof the ginning roller diameter downwardly toward, over and forwardlybeyond the edge of the knife and the rotobar member having outwardlyfacing interconnecting surfaces between the successive blade formationedges shaped to extend from said cylindrical path inwardly to locationsnearer to said center axis effectively forming seed-receiving spacesbetween successive blade surfaces for advancing the seed cottoncoactively with the ginning roller surface toward and over the knifeedge, means for rotating the ginning roller at a predetermined surfacespeed, means for feeding seed cotton to the surface of the ginningroller at a location upstream of said knife edge to cause the ginningroller to strip lint from seeds which are restrained by the knife edgeand convey the lint to a point of removal, and means for rotating saidrotobar member at a speed causing the surface speed of the edges of saidblade surfaces to be slightly less than the surface speed of saidginning roller such as to restrain seeds in said seed-receiving spacesduring seed advancement over said knife edge from said pinch pointtoward a release point while the ginning roller strips lint from suchrestrained seeds and then releasing the seeds from blade restraint atsaid release point spaced from the pinch point a distance whereby thefiber attached to any incompletely ginned seeds in sufficiently heldbetween the knife and ginning roller to cause return of the incompletelyginned seed to the knife edge before the next blade applies advancingforce to the seed, thereby to witdraw substantially all the fibers fromthe seed so long as sufficient fibers remain attached to the seed tocontinue drawing the seed back to the pinch point after each releasethereof, and a narrow strip-like pad of flexible material fixed on andspanning the axial length of each of said outwardly facinginterconnecting surfaces substantially midway between each of thesuccessive blade formation edges to press the seed locks in said seed-receiving spaces between successive blade formation edges against theginning roller surface immediately upstream of said working edge of saidknife and reduce the occurrence of unginned locks.
 2. A roller cottongin as defined in claim 1, wherein the rotobar member includes a groovedsquare cross section bar portion having an elongated recess adjacenteach corner which is a rectilinear trough-like groove of substantiallyV-shaped cross section formed in a respective one of the four flat facesof the square cross section bar portion located at the trailing edge ofthe flat face relative to the direction of rotation thereof, the sidesof said V-shaped grooves nearest said corners forming said forwardlyfacing blade surfaces and lying in planes extending radially from thecenter axis of the bar portion.
 3. A roller cotton gin as defined inclaim 1, wherein the rotobar member includes a grooved square crosssection bar portion having an elongated recess adjacent each cornerwhich is a rectilinear trough-like groove of substantially V-shapedcross section formed in and occupying a minor portion of the area of arespective one of the four flat faces of the square cross section barportion located at the trailing edge of the flat face relative to thedirection of rotation thereof, the sides of said V-shaped groovesnearest said corners forming said forwardly facing blade surfaces andlying in planes extending radially from the center axis of the barportion.
 4. A roller gin as defined in claim 1, wherein the cylindricalpath traversed by the edges of the blade formations has a diameter ofbetween about one-fifth and one-seventh the diameter of the ginningroller.
 5. A roller gin as defined in claim 1, wherein the cylindricalpath traversed by the edges of the blade formations has a diameter inthe range of between about 2.0 and 3 inches and the ginning roller has adiameter of about 15 inches.
 6. A roller gin as defined in claim 1,wherein the cylindrical path traversed by the edges of the bladeformations has a diameter in the range of between about 2.0 and 3 inchesand the ginning roller has a diameter of about 15 inches and the surfacespeed of the edges during ginning being less than but within 90% of thesurface speed of said ginning roller.
 7. A roller cotton gin as definedin claim 1, including a driven auxiliary feed control roller locatedclosely adjacent the surface of the ginning roller spaced apredetermined distance upstream from said rotobar member between thelatter and the region where the seed cotton is fed to the ginning rollersurface to facilitate even flow of cotton between the rotobar member andsaid surface and resist flow of seed cotton over the top of the rotobarmember.
 8. A roller cotton gin as defined in claim 7, including a combstructure adjacent the rotobar member for returning incompletely ginnedcotton seeds to the pinch point for reprocessing comprising a rib-likecomb spanning the blade formations having plural substantiallysemi-circular curved wire fingers arranged in parallel vertical planesextending normal to the axis of said shaft, the wire fingers beinglocated closely adjacent the path of the blade edges substantiallyconcentric therewith and spaced transversely from each other apredetermined distance to pass seeds which have been stripped of linttherebetween but retain in the path of the blades unginned seeds to bereturned by the blades to the pinch point.
 9. A roller cotton gin asdefined in claim 1 including a comb structure adjacent the rotobarmember for returning incompletely ginned cotton seeds to the pinch pointfor reprocessing comprising a rib-like comb spanning the bladeformations having plural substantially semi-circular curved wire fingersarranged in parallel vertical planes extending normal to the axis ofsaid shaft, the wire fingers being located closely adjacent the path ofthe blade edges substantially concentric therewith and spacedtransversely from each other a predetermined distance to pass seedswhich have been stripped of lint therebetween but retain in the path ofthe blades unginned seeds to be returned by the blades to the pinchpoint.
 10. A roller gin as defined in claim 2, wherein the cylindricalpath traversed by the edges of the four corners of the square crosssection portion of said rotobar member has a diameter of between aboutone-fifth and one-seventh the diameter of the ginning roller.
 11. Aroller gin as defined in claim 2, wherein the cylindrical path traversedby the edges of the four corners of the square cross section portion ofsaid rotobar member has a diameter in the range of between about 2.0 and3 inches and the ginning roller has a diameter of about 15 inches.
 12. Aroller gin as defined in claim 2, wherein the cylindrical path traversedby the edges of the four corners of the square cross section portion ofsaid rotobar member has a diameter in the range of between about 2.0 and3 inches and the ginning roller has a diameter of about 15 inches andthe surface speed of the edges of said four corners during ginning beingless than but within 90% of the surface speed of said ginning roller.13. A roller cotton gin as defined in claim 2, including a drivenauxiliary feed control roller located closely adjacent the surface ofthe ginning roller spaced a predetermined distance upstream from saidrotobar member between the latter and the region where the seed cottonis fed to the ginning roller surface to facilitate even flow of cottonbetween the rotobar member and said surface and resist flow of seedcotton over the top of the rotobar member.
 14. A roller cotton gin asdefined in claim 2, including a comb structure adjacent the rotobarmember for returning incompletely ginned cotton seeds to the pinch pointfor reprocessing comprising a rib-like comb spanning the bladeformations having plural substantially semi-circular curved wire fingersarranged in parallel vertical planes extending normal to the axis ofsaid shaft, the wire fingers being located closely adjacent the path ofthe blade edges substantially concentric therewith and spacedtransversely from each other a predetermined distance to pass seedswhich have been stripped of lint therebetween but retain in the path ofthe blades unginned seeds to be returned by the blades to the pinchpoint.
 15. A roller gin as defined in claim 3, wherein the cylindricalpath traversed by the edges of the four corners of the square crosssection portion of said rotobar member has a diameter of between aboutone-fifth and one-seventh the diameter of the ginning roller.
 16. Aroller gin as defined in claim 3, wherein the cylindrical path traversedby the edges of the four corners of the square cross section portion ofsaid rotobar member has a diameter in the range of between about 2.0 and3 inches and the ginning roller has a diameter of about 15 inches.
 17. Aroller gin as defined in claim 3, wherein the cylindrical path traversedby the edges of the four corners of the square cross section portion ofsaid rotobar member has a diameter in the range of between about 2.0 and3 inches and the ginning roller has a diameter of about 15 inches andthe surface speed of the edges of said four corners during ginning beingless than but within 90% of the surface speed of said ginning roller.18. A roller cotton gin as defined in claim 3, including a drivenauxiliary feed control roller located closely adjacent the surface ofthe ginning roller spaced a predetermined distance upstream from saidrotobar member between the latter and the region where the seed cottonis fed to the ginning roller surface to facilitate even flow of cottonbetween the rotobar member and said surface and resist flow of seedcotton over the top of the rotobar member.
 19. A roller cotton gin asdefined in claim 3, including a comb structure adjacent the rotobarmember for returning incompletely ginned cotton seeds to the pinch pointfor reprocessing comprising a rib-like comb spanning the bladeformations having plural substantially semi-circular curved wire fingersarranged in parallel vertical planes extending normal to the axis ofsaid shaft, the wire fingers being located closely adjacent the path ofthe blade edges substantially concentric therewith and spacedtransversely from each other a predetermined distance to pass seedswhich have been stripped of lint therebetween but retain in the path ofthe blades unginned seeds to be returned by the blades to the pinchpoint.
 20. A roller cotton gin comprising a ginning roller having afriction surface for conveying lint fibers to a pinch point station anda fixed knife for separating the lint fibers from cotton seed having anupstream facing working edge at the pinch point located substantiallytangentially of and in contact with the surface of said ginning roller,a rotary stripping blade device comprising a rotary shaft having aplurality of circumferentially spaced radial blades continuouslyspanning the width of the gin, the edges of the blades being located tosweep through a cylindrical path whose diameter is a small fraction ofthe ginning roller diameter downwardly toward, over and forwardly beyondthe edge of the knife, the successive blades effectively formingseed-receiving channels therebetween for advancing the seed cotton overthe knife edge, means for rotating the ginning roller at a predeterminedsurface speed, means for feeding seed cotton to the surface of theginning roller at a location upstream of said knife edge to cause theginning roller to strip lint from seeds which are restrained by theknife edge and convey the lint to a point of removal, means for rotatingsaid stripping blade device as a speed causing the surface speed of theedges of said blade surfaces to be slightly less than the surface speedof said ginning roller such as to restrain seeds in said seed-receivingchannels during seed advancement over said knife edge while the ginningroller strips lint from such restrained seeds and then releasing theseeds from blade restraint at a release point spaced from said knifeedge a distance such that fiber attached to any incompletely ginnedseeds is sufficiently held between the knife and ginning roller to causereturn of the incompletely ginned seed to the knife edge before the nextblade applies advancing force to the seed, thereby to withdrawsubstantially all the fibers from the seed so long as sufficient fibersremain attached to the seed to continue drawing the seed back to thepinch point after each release thereof, the stripping blade deviceincluding a narrow strip-like pad of flexible material spanning theaxial length thereof fixed on a surface of each channel of the strippingblade device positioned substantially midway between each successivepair of blades to press the seed locks in the channels against theginning roller surface immediately upstream of said working edge andreduce the occurrence of unginned locks.
 21. A roller cotton gin asdefined in claim 20, wherein each of said pads are of sponge rubbermaterial of about one-fourth inch thickness fixed to the bottom surfaceof each channel.